docs: replace autotools intructions with meson equivalent

Signed-off-by: Eric Engestrom <eric.engestrom@intel.com>
Reviewed-by: Dylan Baker <dylan@pnwbakers.com>
diff --git a/docs/install.html b/docs/install.html
index 1f83f69..be03890 100644
--- a/docs/install.html
+++ b/docs/install.html
@@ -238,7 +238,7 @@
 <h1 id="pkg-config">7. Building OpenGL programs with pkg-config</h1>
 
 <p>
-Running <code>make install</code> will install package configuration files
+Running <code>ninja install</code> will install package configuration files
 for the pkg-config utility.
 </p>